摘要
应用计算流体动力学(CFD)理论,建立了矩形翅片椭圆管的数学模型,阐述求解的数值计算方法。采用k-ε标准湍流模型、有限体积法(FVM)和SIMPLEC算法,运用FLUENT软件对管外扰流场进行三维数值仿真,得到其阻力特性与换热特性。仿真结果与实验结果相对比,验证了模型的正确性。在此基础上,采用场协同原理分析了温度梯度与速度矢量的夹角对矩形翅片椭圆管换热特性的影响。结果表明:对流换热的强度不仅取决于流体的速度和物性,还取决于速度与温度梯度之间的协同,尽管迎面风速增大,换热得到强化,但随着协同角的增大,换热效率变低,以致换热量非线性增加。
The mathematical model of rectangular finned elliptical tube has been established by using CFD , and the numerical computation method has been elaborated. Then the resistance characteristics and hear transfer characteristics have been tound by three - dimensional numerical simulation of out - tube flow field in accordance with standard k -ε turbulence model, finite volume method （FVM） and SIMPLEC algorithm. The results of simulation and experiments have been compared to verify the correctness of the model. The effects of angle between temperature gradients and velocity vector for heat transfer characteristics have been analyzed by field synergy principle on the base of the model. The results show that the intensity of convective heat transfer depends not only on the speed and fluid properties, but also depends on the synergy between speed and temperature gradient. With the head wind speed increasing, heat transfer has been strengthened, but with synergy angle increasing, heat transfer effieieney has been slowed, whieh results in an increase for non -linear heat capacity.
出处
《制冷技术》
2009年第4期29-32,共4页
Chinese Journal of Refrigeration Technology
关键词
矩形翅片椭圆管
数值模拟
场协同角
计算机仿真
rectangular finned elliptical tube
numerical simulation
intersection angle between velocity and temperature gradients
eomputer simulation
